When Modern Rodding magazine wanted to build a potent 5.3L GM LS engine, it turned to Summit Racing for everything from the rotating assembly to the valve covers. Modern Rodding gave the parts and a bare 5.3L block to American Heritage Performance (AHP), who assembled them into an engine that made 471 horsepower and 422 lbs.-ft. of torque.
You can get an in-depth look at the Bare Block Performance Package LS in the August, September, and October 2022 issues of Modern Rodding. Take a look at the Modern Rodding Bare Block Performance Package 5.3L GM LS Parts Combos and see what it took to build this engine.
A 5.3L iron block was decked and had the cylinders bored and hone bored to 3.810 inch. Back at AHP the block was fitted with Dura-Bond cam bearings, ARP main studs, and a Summit Racing Coolant and Oil Plug Kit.
The rotating assembly features a Summit Racing Pro LS Crankshaft, Pro LS Connecting Rods, and Pro LS Forged Pistons. The crank is forged from 4340 steel and features profiled counterweights to reduce windage plus gun-drilled main journals and drilled rod journals to reduce weight and improve acceleration. The H-beam connecting rods are also forged from 4340 steel and feature ARP 2000 rod bolts.
The Pro LS pistons are forged from 2618 aluminum alloy and have a dished crown with two valve reliefs, and piston skirts that are profiled to run tight piston-to wall-clearances for maximum ring seal and minimal friction. The pistons are fitted with Summit Racing Pro LS Piston Rings that have a 1.5mm plasma-moly coated top ring, 1.5mm ductile iron second ring, and a 3mm stainless steel oil control ring.
Modern Rodding chose a Summit Racing Pro LS Stage 1 Camshaft. Rated at 222°/223° duration @.050 and .600/.575 inches of lift with 115° of lobe separation, the hydraulic roller cam makes excellent power from 2,600 to 6,800 RPM and works well with nitrous oxide or a supercharger. A 2,400 RPM or higher stall torque converter is recommended for use with the Stage 1 cam but not required. The camshaft is mated to a set of Summit Racing Performance LS7 Style Lifters installed with new ACDelco stock replacement lifter trays.
The Summit Racing Pro LS Cast Aluminum Oil Pan is designed to fit an LS engine in a variety of GM cars including 1964-72 A-Bodies, 1967-92 Camaro/Firebird, and 1969-74 Nova. The baffled pan has a 6.2 quart capacity (including filter) and comes with an oil pump pickup tube, fill plug, an oil pump stud, and an oil passage cover. AHP added a Chevrolet Performance windage tray to better control oil aeration, and secured the pan to the block with a Fel-Pro one-piece pan gasket and ARP oil pan bolts.
The factory oil pump was replaced with a Melling high-pressure/high-volume pump. It has a CNC-machined body and cover and longer hardened steel gears for additional oil flow. The pump’s drive and idler shafts extend into the cover to provide additional support and eliminate pump shaft deflection.
The cylinder heads of choice are Trick Flow GenX 205 aluminum heads. The cathedral port heads have a shallower 13.5° valve to decrease valve shrouding, increase mid-lift airflow, and improve rocker arm-to-valve cover clearance. The 205cc intake and 80cc exhaust runners get Trick Flow’s CNC Competition Ported treatment that creates a premium high resolution surface finish for maximum flow and performance.
The GenX 205 cylinder heads also feature CNC-machined 58cc combustion chambers with 2 inch intake and 1.575 inch exhaust valves plus 1.300 inch beehive valve springs rated to handle up to .600 inch of valve lift. The heads were secured to the long block with ARP High Performance Series head bolts and Chevrolet Performance MLS head gaskets.
The cylinder heads were fitted with Summit Racing Pro LS Upgraded Rocker Arms. The 1.7 ratio rockers have heavy-duty cast steel bodies, a captive bearing design and bearing steel trunnions for smoother action and longer life, and improved oil flow to the bearings. Completing the combo is a set of 7.4 inch long Trick Flow Chromoly Pushrods. The one-piece pushrods are 5/16 inch in diameter and have .080 inch thick walls to prevent deflection.
This collection of parts includes a set of Summit Racing Pro LS Valve Covers. The tall-height covers clear roller rocker arms, accept LS2, LS3, or LS7 style coils with 72mm bolt spacing, and come with mounting hardware, gaskets, and a nifty billet aluminum oil fill cap. The 5.3L also got a Chevrolet Performance valley cover, a Fel-Pro front cover gasket set and rear main seal, and a quintet of sensors:
• Delphi camshaft and crankshaft position sensors
• Chevrolet Performance knock sensors (2 required)
• ACDelco coolant and oil pressure sensors
Modern Rodding assembled a collection of tools from Summit Racing to build the 5.3L. The Summit Racing LS Main Cap Puller allows you to remove the caps in one simple motion without damaging the caps or the bearings. The Summit Racing Cam Bearing Installation Tool is designed just for LS engines, and the Summit Racing™ Flywheel Holding Tool keeps the crankshaft from rotating so you can easily install or remove harmonic dampers, flexplates, and flywheels.
A Summit Racing Dial Bore Gauge was used to check the inside diameter of the main bearing caps to insure they were within spec. Piston ring gap was set with a Summit Racing Piston Ring Squaring Tool and USA-1 Piston Ring Filer. The billet aluminum squaring tool is machined to be flat and parallel within .001 of an inch so ring gaps are accurate and consistent.
Rounding out our toolbox is a Summit Racing™ Adjustable Ring Compressor, a Powerbuilt harmonic damper installation tool, and a COMP Cams pushrod length checker.
COMPANY DETAILS |
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Summit Racing Equipment |
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Contact |
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Phone |
(800) 230-3030 |
Address |
P.O. Box 909 |
Akron, OH 44309 |
Summit Racing Equipment was founded in 1968 as a part-time parts business in Stow, Ohio. Today, Summit Racing Equipment is one of the world’s largest supplier of automotive-performance-equipment company, and offers thousands of performance parts, aftermarket accessories, OEM parts, tools and garage equipment. Summit Racing’s goal is to give customers the parts they want at a fair price, deliver those parts fast, and back them with the best customer service on the planet.
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